The assignee of the present invention manufactures and deploys spacecraft for, inter alia, communications and broadcast services from geostationary orbit. Payload systems of such spacecraft conventionally employ input multiplexers to channelize a radio frequency band of electromagnetic energy into a set of channels by use of a filter bank. The mass, efficiency, cost, and complexity of a multiplexer are important factors in determining the overall performance of the payload system.
Known input multiplexers couple the filter bank to an input RF signal by way of waveguide or coaxial manifolds that may or may not include circulators, as disclosed, for example, by Edridge, U.S. Pat. No. 4,688,259, assigned to the assignee of the present invention and incorporated by reference herein in its entirety. Such techniques result in multiplexer designs of substantial size and weight, and are difficult or impossible to tune once integrated.
As a result, improved multiplexer designs are desirable.